EXTENSIVE REVIXION that is more then 50% of the content could mean 2 things: (1) the journal is low quality that it is not willing to reject low quality article which it already deems more than 50% is not satisfactory, or (2) the article needs to be rewritten, not revised. In the first case, the author needs to look for better journal. In the second case, rewrite the article. The data may be good, but the writing may be substandard. If the data is inadequate, no matter how good the writing may be, the article is always questionable.